This invention relates generally to a unique means for connecting two ends of a belt, and, specifically, to a novel construction of a zipper used to join two ends of a conveyor belt. In many modern businesses, conveyor belts are used extensively. Many assembly lines employ conveyor belts in one way or another. Also, airlines and parcel services utilize conveyor belts to move cargo. Many of those conveyor belts operate around the clock. The employment of the conveyor belt has expanded to encompass almost every aspect of modern business.
Given the wide variety of uses for conveyor belts, and, more importantly, the length of the time periods of those uses, it is very important to have a conveyor belt that is reliable. Conveyor belts that have poor construction, especially in the means for connecting the two ends of the conveyor belt, are an unwanted liability to the modern businessman. Many problems are caused by a defective, or weakly constructed belt.
Specifically, conveyor belts are subject to great stress, and tension forces throughout the work day and beyond. The belt carries a large load, which adds a significant, gravitationally generated, force to the belt, which often compresses the belt against the rollers. This force is highly dangerous to the structural integrity of the belt.
When the belt rotates around an end roller at the end of the conveyor belt assembly, the gravitational force of the load generates a tension force directed opposite to the direction of belt travel. When the joint, or zipper, connecting the two ends of the conveyor belt rotates around the end roller, it too is subjected to the same tension force.
The actions of this force, compounded by the rotation of the zipper around the end roller, tend to cause the zipper to become undone, thereby breaking the connection between the two ends of the conveyor belt. When this happens, the conveyor experiences significant down time while an operator removes the load from the belt, and attempts to redo the zipper. This down time is reflected is decreased efficiency of, and decreased profits generated by the business, which is unacceptable to the modern businessman.
The prior art contains many belts which do not have connecting means having appropriate stiffness to prevent opening of the zipper. Therefore, a means for connecting the two ends of a conveyor belt which can withstand the effects of the tension force is desired. However, the need for the means to have strength when the belt is under tension must be balanced against the need for the means to flex around an end roller. Specifically, a zipper that is sufficiently stiff to withstand the propensity to become undone as it travels over an end roller, while also being sufficiently flexible to rotate easily over an end roller is desired.